When to Plant in Littleton, CO

In Littleton, gardeners enjoy a growing season marked by a median last spring frost date of May 17 and a median first fall frost date of September 27, resulting in 133 frost-free days. This timing encourages careful planning to maximize the growing potential of various crops throughout the productive months. Local gardeners should prepare beds and plan their planting schedules around these frost dates, ensuring optimal growth for both cool and warm-season crops.

Littleton's continental mountain microclimate presents unique gardening opportunities thanks to its cold nights and intense sun. Vegetables such as peppers and tomatoes thrive due to the warm daytime temperatures, while night temperatures help preserve flavor and juice content. Conversely, crops like lettuce and spinach may struggle with the significant temperature fluctuations, leading to bolting in the heat of the day and poor growth patterns.

What to plant now in Littleton

Spring: Plant cool-season crops like peas and radishes as soon as the soil can be worked, typically in early April, to take advantage of the frost-free days before the May 17 last frost.
Summer: Start warm-season crops like beans and squash indoors by early May and transplant after the May 17 last frost, ensuring ample time for growth before the growing season peaks.
Fall: Begin planting appropriate fall crops like kale and brussels sprouts by mid-August to ensure they are well established before the September 27 first fall frost.
Winter: Use December as a time to prepare garden beds and optimize soil health for the upcoming spring planting season by adding organic matter and planning out your crop rotation.

In Littleton (133 frost-free days, a moderate season), 37 of 56 planner crops fit outright, 16 get two plantings, 2 need an indoor start, 1 crop is perennial.

Month by month in Littleton

Month	What to do
January	In January, the gardening world is quiet. Consider planning your garden layout and researching seed varieties. Use this time for indoor gardening activities like starting herbs on windowsills.
February	February can still be cold in Littleton, but it’s time to finalize seed orders and prepare for starting seedlings indoors. Check your supplies for pots and growing medium.
March	As temperatures slowly rise in March, start sowing cool-season crops indoors, such as broccoli and cabbage, to be ready for spring planting once the soil thaws.
April	April is an exciting month to get the garden ready. Prepare garden beds by adding compost and nutrients as soon as the soil is workable, usually by mid-April.
May	May marks a pivotal time with the last spring frost date on May 17. Plant warm-season crops like tomatoes and peppers after this date to avoid frost damage.
June	With the growing season in full swing, June is perfect for tending to the garden. Ensure your plants are well-watered and manage weeds, providing summer crops room to flourish.
July	In July, heat can be intense. Regular watering is crucial for sustaining crop health. Harvest early crops and prepare for fall planting, considering which varieties to continue.
August	August requires attention to harvesting and preparing for fall. Start planting cooler crops like kale by mid to late August to ensure their establishment before the first fall frost in late September.
September	As September approaches, gardeners should be vigilant for the first fall frost date on September 27. Harvest remaining warm-season crops and continue tending to fall plantings.
October	With October in full swing, focus on cleaning up garden beds and preventing pests. It’s time to plant garlic for the next season and prepare soil for winter.
November	November signals the end of the gardening year. Clear any debris from your garden and put perennials to bed, ensuring good care to prepare for winter's rest.
December	December is a time for reflection and planning. Review your garden successes and failures from the past year while organizing seeds and tools for the next year's adventures.

Frost dates for Littleton ZIP codes

ZIP	Last spring frost (50%)	First fall frost (50%)	Zone
80126	May 17	September 27	6a
80122	May 17	September 27	6a
80120	May 13	September 29	6a

FAQ

When is the last frost in Littleton?

The last frost in Littleton typically occurs on May 17, making this an important date for gardeners planning their spring planting.

What vegetables grow best in Littleton?

Vegetables like tomatoes, peppers, and cucumbers thrive in Littleton's warm daytime temperatures and cool nights, while leafy greens can struggle with heat.

When should I plant tomatoes in Littleton?

Tomatoes should be planted after the last frost date of May 17. Start seedlings indoors 6-8 weeks prior for the best yield.

Can I garden year-round in Littleton?

While gardening is limited in winter, using cold frames and planning for spring crops can allow for some year-round gardening in Littleton.

How does Plan My Garden help Littleton gardeners?

Plan My Garden offers tailored advice on planting times based on local frost dates and microclimates, helping gardeners maximize their harvest.